If an unknown element has a mass number of 14 and 7 neutrons how many protons are there

There are 7 protons. The mass number is the addition of all protons and neutrons in a given element. To find the protons, simply subtract the mass number by the neutrons. 14-7 neutrons= 7 protons

That result from subduction of oceanic plates beneath lighter continental plates. most of the earth's volcanoes are located around the pacific ring of fire because that the location of most of the earth's subduction zones.

m=9

step-by-step explanation:

7m+8=71 subtract   8 from 71 which is 63 than divide it by 7m   equal 9.